Fix I2C slave test on STM32 (#455)

* Start testing STM32U0 with test shield, make a few fixes

* Fix I2C slave not working on STM if you set the frequency after initializing

* Add handling of a partial write by the master

* Fix wording

Author: multiplemonomials

hal/include/hal/i2c_api.h

@@ -323,7 +323,7 @@ int  i2c_slave_receive(i2c_t *obj);
  *  @param obj The I2C object
  *  @param data    The buffer for receiving
  *  @param length  Number of bytes to read
- *  @return non-zero if a value is available, or zero on error
+ *  @return Number of bytes read, or zero on error
  */
 int  i2c_slave_read(i2c_t *obj, char *data, int length);
 

targets/TARGET_STM/TARGET_STM32U0/stm_dma_info.h

@@ -26,10 +26,10 @@
 
 /// Mapping from SPI index to DMA link info for Tx
 static const DMALinkInfo SPITxDMALinks[] = {
-        {1, 0, DMA_REQUEST_SPI1_TX},
-        {1, 2, DMA_REQUEST_SPI2_TX},
+        {1, 2, DMA_REQUEST_SPI1_TX},
+        {1, 4, DMA_REQUEST_SPI2_TX},
 #if defined (SPI3)
-        {1, 4, DMA_REQUEST_SPI3_TX}
+        {1, 6, DMA_REQUEST_SPI3_TX}
 #endif
 };
 

targets/TARGET_STM/i2c_api.c

@@ -548,6 +548,17 @@ void i2c_init_internal(i2c_t *obj, const i2c_pinmap_t *pinmap)
         obj_s->hz = 100000;    // 100 kHz per default
     }
 
+    // Set remaining init parameters to defaults
+    obj_s->handle.Init.AddressingMode  = I2C_ADDRESSINGMODE_7BIT;
+    obj_s->handle.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
+    obj_s->handle.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
+    obj_s->handle.Init.NoStretchMode   = I2C_NOSTRETCH_DISABLE;
+    obj_s->handle.Init.OwnAddress1     = 0;
+    obj_s->handle.Init.OwnAddress2     = 0;
+#ifdef I2C_IP_VERSION_V2
+    obj_s->handle.Init.OwnAddress2Masks = I2C_OA2_NOMASK;
+#endif
+
     // Reset to clear pending flags if any
     i2c_hw_reset(obj);
     i2c_frequency(obj, obj_s->hz);
@@ -784,19 +795,15 @@ void i2c_frequency(i2c_t *obj, int hz)
     /* hz value is stored for computing timing value next time */
     obj_s->current_hz = hz;
 #endif // I2C_IP_VERSION_V2
-
-    // I2C configuration
-    handle->Init.AddressingMode  = I2C_ADDRESSINGMODE_7BIT;
-    handle->Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
-    handle->Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
-    handle->Init.NoStretchMode   = I2C_NOSTRETCH_DISABLE;
-    handle->Init.OwnAddress1     = 0;
-    handle->Init.OwnAddress2     = 0;
-#ifdef I2C_IP_VERSION_V2
-    handle->Init.OwnAddress2Masks = I2C_OA2_NOMASK;
-#endif
+    
     HAL_I2C_Init(handle);
 
+    // In slave mode, reenable slave interrupts after calling init
+    if(obj_s->slave != 0)
+    {
+        HAL_I2C_EnableListen_IT(&obj_s->handle);
+    }
+
     /*  store frequency for timeout computation */
     obj_s->hz = hz;
 }
@@ -1120,11 +1127,11 @@ int i2c_byte_read(i2c_t *obj, int last)
     if (last) {
         /* Disable Address Acknowledge */
         tmpreg = tmpreg & (~I2C_CR2_RELOAD);
-        tmpreg |= I2C_CR2_NACK | (I2C_CR2_NBYTES & (1 << 16));
+        tmpreg |= I2C_CR2_NACK | (1 << I2C_CR2_NBYTES_Pos);
     } else {
         /* Enable reload mode as we don't know how many bytes will be sent */
         /* and set transfer size to 1 */
-        tmpreg |= I2C_CR2_RELOAD | (I2C_CR2_NBYTES & (1 << 16));
+        tmpreg |= I2C_CR2_RELOAD | (1 << I2C_CR2_NBYTES_Pos);
     }
 
     /* Set the prepared configuration */
@@ -1505,15 +1512,15 @@ void HAL_I2C_ErrorCallback(I2C_HandleTypeDef *hi2c)
     uint32_t event_code = 0;
 
 #if DEVICE_I2CSLAVE
-    uint32_t address = 0;
-    /*  Store address to handle it after reset */
-    if (obj_s->slave) {
-        address = handle->Init.OwnAddress1;
+    if(obj_s->slave_rx_transfer_in_progress && handle->ErrorCode == HAL_I2C_ERROR_AF) {
+        // We get here if the master ended a write operation after fewer than expected
+        // bytes. Just mark the slave transfer as done and return.
+        obj_s->slave_rx_transfer_in_progress = 0;
+        return;
     }
 #endif
 
-
-    if ((handle->ErrorCode & HAL_I2C_ERROR_AF) == HAL_I2C_ERROR_AF) {
+    if (handle->ErrorCode & HAL_I2C_ERROR_AF) {
         /* Keep Set event flag */
         event_code = (I2C_EVENT_TRANSFER_EARLY_NACK) | (I2C_EVENT_ERROR_NO_SLAVE);
     }
@@ -1528,6 +1535,14 @@ void HAL_I2C_ErrorCallback(I2C_HandleTypeDef *hi2c)
 
     DEBUG_PRINTF("HAL_I2C_ErrorCallback:%d, index=%d\r\n", (int) hi2c->ErrorCode, obj_s->index);
 
+#if DEVICE_I2CSLAVE
+    uint32_t address = 0;
+    /*  Store address to handle it after reset */
+    if (obj_s->slave) {
+        address = handle->Init.OwnAddress1;
+    }
+#endif
+
     /* re-init IP to try and get back in a working state */
     i2c_init_internal(obj, NULL);
 
@@ -1710,7 +1725,7 @@ int i2c_slave_read(i2c_t *obj, char *data, int length)
             if (obj_s->slave == SLAVE_MODE_LISTEN) {
                 count = obj_s->slave_rx_count;
             } else {
-                count = _length;
+                count = length - handle->XferCount;
             }
         } else {
             DEBUG_PRINTF("TIMEOUT or error in i2c_slave_read\r\n");

targets/targets.json5

@@ -4803,10 +4803,6 @@ mode is recommended for target MCUs with small amounts of flash and RAM.",
             "TRNG",
             //"USBDEVICE" // TODO
         ],
-        "device_has_remove": [
-            "I2C",      // Not tested just prepared
-            "I2CSLAVE"  // Not tested just prepared
-        ],
         "is_mcu_family_target": true
     },
     "MCU_STM32U083xC": {

tools/cmake/upload_methods/UploadMethodOPENOCD.cmake

@@ -48,7 +48,8 @@ function(gen_upload_target TARGET_NAME BINARY_FILE)
 		${OPENOCD_ADAPTER_SERIAL_COMMAND}
 		-c "gdb_port disabled" # Don't start a GDB server when just programming
 		-c "program ${BINARY_FILE} ${MBED_UPLOAD_BASE_ADDR} reset exit"
-		VERBATIM)
+		VERBATIM
+		USES_TERMINAL)
 
 endfunction(gen_upload_target)